How much KR is expected from a stock motor?

[Fireball]

Hey all.

I'm just throwing this question out there...
I have a 2001 Malibu with a 3100.
I've got a 65 mm TB, ported UIM, CAI and 2.5 mandrel bent catback.

Now I went to the track this past weekend and was not getting particularly good numbers.

Quickhatch from this site scanned my car with hptuners and found that I had I believe 4 degrees of KR in first and up to 9 degrees in 3rd gear!

Now these numbers seem high to me; however I don't really have anything to compare against....

Would a stock motor have this much KR? Is this KR as a result of needing a tune? Lingering issues with the car?

Just curious your thoughts on this!

Thanks!

[mickaz]

the problem with the stock tune is it's a general tune for a car in Canada and another in Arizona.
when you have knock it could be a lot of stuff ( some even combining) like lack/too much fuel,transmission noises,not accurate Maf table VE table and too much timing ( which i believe is the case with 3100-3400.) on my car it was the transmission that was giving lot of Kr but i was able to find out because it would happen always in the same condition at the same rpm ( at cruise when the Tcc locks)

[Fireball]

Thats fair enough..
That brings another question to mind for me...
If you do a tune in say the summer (or winter); does this imply that it may not be effective in the next season?

Also, is the amount of KR I'm seeing holding me back just a little, a lot? How much is the impact?

[1988GTU]

What octane were you running at that time of KR?

[Fireball]

Regular grade..still seems much no?
Is it possible to quantify at all how much this holds (Held) me back?

My track times were not good...
I only ran a best of 16.01 at 85 mph...

The thing that bothers me is that I read threads where guys with grand ams were doing 15.4-15.6 at 86 mph...
Grand Am's have more agressive greaing (GT's atleast); I mean sure part of it is launch but with such a low power car do I really lose that many tenths?

Just trying to figure out whats up here... Do I need a tune? Is something up with the car?
I plan on getting a tune either way just trying to track down other problems while I'm at it...if there are problems and the thing simply isn't just damn slow!

[1988GTU]

Can you clarify what regular grade means? It could be a variation of octanes.

[Fireball]

Apologies, I meant 87 octane.

Thanks

[1988GTU]

Try using 100% 92 octane not blending it with anything else and go do exactly what you did to try and register that kr again while using that 92 octane.

[mickaz]

but 16.01 on a 3100 with only a TB is good time...but what you did is change th Volumetric efficiency and the Maf table of your car.
before paying for tuning I highly uggest you do a headder on your car and after you tune...the biggest gains will come from the exhuast I guarantee it. i don't really tune for winter since i don't care about performance. but summer nights is the best time to tune.

[Fireball]

but 16.01 on a 3100 with only a TB is good time...but what you did is change th Volumetric efficiency and the Maf table of your car.
before paying for tuning I highly uggest you do a headder on your car and after you tune...the biggest gains will come from the exhuast I guarantee it. i don't really tune for winter since i don't care about performance. but summer nights is the best time to tune.

I just thought I'd be doing better considering motor week ran a 15.7 in a 3400 Alero.. I mean there's barely a difference between the engines; hell in the n-body it's even less of a difference between 3100 and 3400 (170 to 175 hp).
I also did a 2.5 catback which dynoed + 10 fwhp on a stock Grand Am GT, I don't expect that much but at least close..

I am looking to do headers; they're just hard to find....being in Canada doesn't make it any better..

I do plan a tune after headers...

I've also got a 3500 UIM with plenum spacers ready to go on....
You've got one of those correct? How did you find that difference wise? I know they'll likely flow similarly (I was thinking maybe my 3100 may even flow better because its P&P, although apparently the 3500 one is too although that's just what the buyer told; I believe him but I don't know to what extent it was)....I was just wondering if it would help powerband..

[SappySE107]

You need tuning. We can only get about 20 degrees advance on a stock cam/head 3400 with headers and ported manifolds and a 65mm TB using 87 octane. It is what it is and the stock tune is really not very good at all. KR ruins performance.

[mickaz]

I just thought I'd be doing better considering motor week ran a 15.7 in a 3400 Alero.. I mean there's barely a difference between the engines; hell in the n-body it's even less of a difference between 3100 and 3400 (170 to 175 hp).
I also did a 2.5 catback which dynoed + 10 fwhp on a stock Grand Am GT, I don't expect that much but at least close..

I am looking to do headers; they're just hard to find....being in Canada doesn't make it any better..

I do plan a tune after headers...

I've also got a 3500 UIM with plenum spacers ready to go on....
You've got one of those correct? How did you find that difference wise? I know they'll likely flow similarly (I was thinking maybe my 3100 may even flow better because its P&P, although apparently the 3500 one is too although that's just what the buyer told; I believe him but I don't know to what extent it was)....I was just wondering if it would help powerband..

the tune in the alero is way different and the 3400 is a very strong engine.
you will not see alot from a 3500 UIM. headders is the best bang for the buck and a tune...what I recommend is starting with eh biggest engine and start from there.

[Fireball]

I agree that I wont see much but I already have it and was hoping I'd at least get a better power band going.
I agree that the 3400 is a good engine but aside from displacement there is no real difference between it and a 3100...

I really don't want to pull an engine unless it's broken really...
Headers are my next mod as soon as a reasonable pair pops up!

[mickaz]

I agree that the 3400 is a good engine but aside from displacement there is no real difference between it and a 3100...

Power is the one and only difference you need LOL

[AleroB888]

I just did a scan today on my bone stock 2003 Alero. It has 29K miles on it, ambient temp 60-70 degrees. It had not been run in a couple weeks. Fuel trims were in the negative range. It can run a 15.9 quarter on a 75 degree day. No tuning done to it, I offer it up just as one example.